In recent years, individual recognition technology has received a lot of attention. For example, there is a technology to be used for production, management, and the like in which information such as a history of the object is clarified by giving an ID (an individual recognition number) to an individual object. Above all, the development of semiconductor devices that can send and receive data without contact has been advanced. As such semiconductor devices, an RFID (Radio Frequency Identification) (also referred to as an ID tag, an IC tag, and IC chip, an RF (Radio Frequency) tag, a wireless tag, an electronic tag, or a wireless chip) and the like are beginning to be introduced into companies, markets, and the like.
Many semiconductor devices put to practical use today, such as RFID, include element groups having circuits including transistors and the like (also called IC (integrated circuit) chips) and conductive films functioning as antennas. These semiconductor devices can carry out data exchange between reader/writers via the antennas by electromagnetic waves.
In general, in the foregoing semiconductor devices, the conductive films functioning as antennas are formed using a method such as a winding method, an embedding method, a printing method, an etching method, a plating method or the like. Among these methods, using a screen printing method in particular is advantageous in terms of manufacturing cost and throughput, since the number of process steps and the number of necessary devices are small and a manufacturing method is relatively simple.
As shown in FIGS. 14A and 14B, the screen printing method is a method of forming a desired pattern on a surface of a printing object by using a screen printing plate 810, which has a wire netting (mesh) 804 and an emulsion 803 for a mask inside of a frame 801 and an opening portion 802 provided by selectively removing the emulsion 803, to push out a paste 806 by a squeegee 805, a roller, or the like over the printing object (here, an element group 102.)
In this manner, the screen printing method is widely used for formation steps of a conductive film, a pixel electrode, or the like included in a transistor or the like, in addition to, of course, a conductive film functioning as an antenna (for example, Patent Document 1: Japanese Patent Laid-Open No. H9-1970).